Using pingers to reduce bycatch of small cetaceans in Peru's small-scale driftnet fishery

Acoustic pingers (Dukane Netmark 1000; frequency of 10-12 kHz and emit 300 ms tone every 4 sec with a source level range of 120-146 dB) were assessed to determine the effectiveness for reducing bycatch of dolphins and porpoises (common dolphins, dusky dolphins, bottlenose dolphins, Burmeister's porpoise, and pilot whales) by Peruvian small-scale driftnet fleets. Pingers were tested between April 2009 and August 2011. Twenty-two percent of the control nets captured small cetaceans and 16% of experimental nets captured small cetaceans. This was a 37% reduction in bycatch rates, suggesting that pingers may be effective in reducing bycatch of small cetaceans in this fishery. Catch rates of the fishery's target shark and ray species was not changed.